Abstract The goal of the Histology and Molecular Pathology Core is to provide a common facility and expertise for the broad spectrum of morphologic studies that may be required for interpretation of studies of various models of kidney disease and their response to interventions. Additional major functions of this Core include providing tissue samples from existing archival specimens from various kidney disease models that may be used for exploration and characterization of expression patterns of various novel target molecules (tissue microarrays). The Core also aims to develop approaches and enhance existing morphologic techniques to improve the ability of center investigators to localize specific molecules in tissue sections, and to interpret their significance based on the spatial localization and relationship to patterns of injury (e.g. mass spectrometry imaging). The principal morphologic techniques provided by the Core include routine histology, including special stains, and selected immunohistochemistry stains and novel RNA scope in situ hydridization. In addition, electron microscopic analysis and selected morphometric techniques, including glomerular size, tubulointerstitial fibrosis, GBM width and foot process effacement are provided. Laser capture microscopic dissection for special studies of selected renal structures is also offered, with mass spectrometry and/or PCR for molecules of interest in the selected regions. Confocal Z section imaging of selected renal structures for detailed spatial analysis can also be performed by the Core. We already have successfully developed mouse and rat kidney tissue array samples from a wide range of experimental models for assessment of key novel molecules and their response to interventions. We have begun development of in situ mass spectroscopy techniques to optimize spatial resolution of mass spectra in kidney tissues, and propose to fully develop this technique for identification of key molecules in kidney diseases. Thus, the Core will continue to offer both state-of-the-art and standard morphologic assessments, together with development of novel approaches to assess specific molecules in tissue sections, and to interpret their significance based on the spatial localization and relationship to patterns of injury.